Immobilized enzyme derivatives serve as specific, easily removable catalysts, that can be used repeatedly in columns and in batch reactors. A large number of immobilized enzyme systems have been described in the literature (see for example Goldstein L. and Katchalski E, Z. Anal. Chem. 243 (1968) 375).
Most of the natural hydrophilic polymers used for the covalent binding of enzymes are polysaccharides (e.g. derivatized celluloses or cross-linked dextrans) and their chemical reactivity and mechanical stability and are limited by the properties of the monomer unit. Synthetic polymeric carriers offer a much wider range of properties, which can be adapted to specific needs by appropriate modification of the chemical composition of the material. In many cases, however, derivatives of enzymes bound to synthetic polymers exhibit low temperature and lyophilization stabilities, presumably due to the hydrophobic nature of the support.